You can tell by the way he says this that thousands of astronomy and enology students must have written this advice down, making him perhaps the only astro-enologist in Santa Cruz County.

Miller has been at UC Santa Cruz since 1967. He is the former director of Lick Observatory on Mount Hamilton and had oversight of the Keck Observatory in Hawaii on behalf of the University of California, playing a major role in the building of the world's largest infrared and optical telescopes and their instruments. He was also deeply involved in the conceptual stages of the proposed 30-meter telescope and instruments to improve resolution, imaging and optics. Though retired, he continues research at UC Santa Cruz on astronomical instruments.

A home winemaker and a connoisseur of French wines, Miller also taught a series of popular enology classes at the university in the 1970s, and later through UC Extension. Winemakers such as Ed Muns [Muns Vineyard] and Jim Schultze [Windy Oaks] were students.

The Westside resident muses about 40 percent of those students went into the wine business and wonders how many astronomy students kept it up.

"Joe's lab is a glass, his nose and tongue," says business partner Kurt Grutzmacher.

When Grutzmacher tasted Joe Miller's homemade pinot noir at a neighbor's gathering 12 years ago, he was ready to start a business in order to share Miller's wine with the world.

"The minute the grapes are picked, they are at 100. Anything you do takes off points. You are to do no harm. The less you do the better," he says.

"During fermentation Miller punches down the crushed red grapes himself in open-topped fermenters in the old style. When the wines are pressed at the end of fermentation, they spend the rest of their lives in barrels, sometimes the same barrel. They are never fined or filtered, and racking is kept to a minimum."

And though Miller has no vineyards, he likes to "cultivate growers, not grapes," buying from Muns, Dancing Creek [formerly Trout Gulch] and Regan Vineyards. His current favorite is the pinot noir grown in the limestone soils of John Fambrini's vineyard, near Western Avenue just north of Santa Cruz.

He says, "Bonny Doon is potentially the best place to grow grapes in the Western hemisphere" and that "Corralitos is superb."

And what of the increasingly popular biodynamic approach to growing grapes, which takes in the ecological, energetic and spiritual aspects of a piece of land? The astrophysicist calls it "nonsense." He says he won't be burying any cow horns soon -- a regular practice in biodynamics -- though he does believe in standard organic farming practices.

Miller has a firm belief in matching grapes to soil and climate, and says that Santa Cruz Mountains growers are just now finding the right spots, a process that took centuries in France.

"The Santa Cruz Mountains provides unique microclimates, cooling by the ocean, warming by the sun. You can plant grapes in a climate absolutely suited to them," he says.

AT A GLANCE

Rexford Winery

What: Rexford Winery, owned by astronomy professor Joe Miller, started as Hillcrest Terrace in 2008. It was named after the street he lives on. After an Oregon winery trademarked the word 'hillcrest,' Miller changed it to Rexford, the street he grew up on. Partner Kurt Grutzmacher handles the business end.Tasting room: 429-B Ingalls St., Santa Cruz, at the corner of Swift Street. Wine club available.Hours: Noon to 5 p.m. Saturdays, 2-5 p.m. Sundays, and by appointment.I make wines that: 'I like to drink…. That accurately reflect the varietal characteristics of the grapes and the unique microclimates and soils of the vineyards from which they come,' says Miller.Wines: Single vineyard pinot noir, chardonnay, merlot and other premium varietals.Family: Miller's wife Nina is a quilter; daughter Miriam, a speech therapist; and son Sam, associate winemaker who is also pursuing a doctorate in jazz. Grutzmacher has two children Ruby, 10, Leo, 7.Outside the winery: Miller enjoys his research projects at UC Santa Cruz, collecting vinyl records, traveling to wine regions and is an avid photographer. Grutzmacher is chairman of Next Space, enjoys sailing, mountain biking and surfing.Inspired by: 'Santa Cruz Mountains has the possibility to make the finest California wines, judged by Old World standards,' says Miller.Produces: 700-800 cases a year.Winemaker selection: 2009 Pinot Noir, Santa Cruz Mountains, Fambrini Vineyard. Notes: 'Taste is full-bodied with hints of plums, berries and cherries, but the overall taste is dominated by intense pinot noir flavors, with a superb acid balance.' $34.Recommends: Equinox WineryContact: 426-1500 and www.rexfordwinery.com